I may have a break through in the FCP to DVDA problem.
My former workflow was to export the QT movie using ProRes 422 to a Mac Extended Journaled HD. A short clip would be recognized by DVDA but not a 30 minute movie.
I formatted an external HD to Windows FAT using Mac Disk Utility.
Both the short clip and the 30 minute movie now work in DVDA. I have the latest versions of QT in both Windows and Mac. Only one problem, Vegas 9.0c plays the imported QT movie audio but the video is black. The movie plays fine in Windows QT player.